Pull-off and clamp for thread cutters



Aug. 3, 1948., TURNER 2,446,444

PULL-OFF AND CLAMP FOR THREAD CUTTERS Filed March 6, 1946 IN V E NTO R RICHARD 6. TURNER ATTORNEY Patented Aug. 3, 1948 PULL-OFF AND CLAMP ron THREAD CUTTERS Richard G. Turner, Worcester, Mass, assignor to Crompton, & Knowles Loom Works, Worcester, Mass., a corporation of Massachusetts Application March 6, 1946, Serial No. 652,405

1 Claim.

This invention relates to improvements in thread cutting mechanism for looms and it is the general object of the invention to provide an improved form of clamp for the thread. In weft replenishing looms it is necessary to cut the thread of. the outgoing bobbin at a point between the selvage and the bobbin so that part of the thread can be drawn out of the shuttle eye by the descending ejected bobbin. The other part of the thread extends from the cutter to the selvage and should be clamped or in some other way held so that it will not be drawn into the cloth to form an imperfection. In a type of thread cutter which has gone into extensive use provision ismade for clamping and cutting the thread, but as heretofore made this type of cutter has not worked entirely satisfactorily with strong relatively inelastic yarns. The reason for this failureis due to. pulling of thethread out of the clamp when the cutter is returned to its normal forward position. During this forward movement the cutter moves away from the fell and the resultant tension on the thread dislodges it from the clamp.

It is an important object of my present invention to provide an auxiliary clamp which shall also act as a pulloff to draw an additional amount of yarn from the bobbin prior to cutting. The eifect of the auxiliary clampis to hold an increased length of thread so that even though the thread should slip somewhat when the cutter mechanism is returning to its normal position, some part of the thread will nevertheless remain clamped.

It is another object of the invention to provide improved means by which force may be exerted through the auxiliary clamp against the moving cutter jaw or blade to hold the latter tightly against the stationary blade. This feature of the invention includes a small bushing or sleeve which not only transmits spring pressure to the moving cutter blade, but also serves as a pivot for the auxiliary clamp.

Thread cutters of the type to which this invention more particularly relates have ordinarily been made with leaf springs which hold the primary or main clamp and the cutting jaw in close relationship. It is a further object of the invention to provide an auxiliary clamp so constructed that this leaf spring will not only perform its former functions but also hold the auxiliary 2 clamp during the cutting and clamp-ing operations of the mechanism. 1 A

With these and other objects in view which will appear as the description proceeds, my invention resides in the combination and arrangement of parts hereinafter described and set'forth.

In the accompanying drawings, wherein .a convenientembodiment of my invention is set forth,

.Fig. 1 is'a diagrammatic plan viewv showing the cloth in a loom, the cutter and clamp provided with my present invention, and a shuttle'carrying a depleted bobbin from which the thread'to be cut extends to the cloth,

Fig. 2 is a side elevation on an enlarged scale looking in the direction of arrow 2, Fig.1, showing the cutter and clamping mechanism in "normal closed forward position,

Fig. 3 is a perspective view of the thread cutter .and its mounting, showing the cutter and clamp in rear open position,

Fig. 4 is an exploded view of the several parts of the thread cutting and clamping mechanism suggesting the manner in which they are assem bled and also their relative positions, and

Fig. 5 is a vertical section on line 5-5 of Fig. 2. Referring particularly to Fig. 1, the cloth Iii, warp ll, fell l2 and selvage l3, shuttle l4 and bobbin l5 are shown in the relative positions they occupy during a weft replenishing operation. The weft thread W;to be cut extends from the shuttle eye [6 to the fell and selvage. Located between the shuttle and the cloth is a cutting and clamping mechanism 20 which is ordinarily in the full line position shown in Fig. l,'but when a replenishing operation occurs mechanism 20 is moved rearwardly to the dotted line position where it can cut and clamp the weft thread W. The thread cutter and clamp is then returned to its normal forward position in which'it is farther from the fell than when in its rearward position. A strand of weft W extends from the fell .to the mechanismiil and should be held until it can be cut at the selvage by the usual form of selyage cutter not shown. When the yarn W is elasticv it may stretch sufiiciently so that the strand W can be held in the clamp as heretofore made, but when the weft is strong and relatively inelastic,; the right end of the strand W as viewed 'inx-Figi 1 is likely to slip out of the clamp heretofore made.

As shown in Fig. 3 the mechanism zu ismounted on a carrier 2! pivoted as at 22 to a lever 23. The latter has provision as at 24 for pivotal mounting on a stationary stud (not shown), and a rearwardly extending arm 25 on lever 23 is adapted for connection with a vertically extending rod (not shown) by which the cutter and clamp is moved. A rod 26 extends upwardly from the cutter and clamp mechanism and is pivoted to a stationary stud (not shown) spaced from the axis of lever 23 so that as the mechanism 20 moves rearwardly *there will 'be a .diflerential anovement'between it and the lower end of rod'25.

The carrier 2| has a supporting head A to which is held a stationary cutter blade B for cooperation with a pivoted cutter bladeC. A-c1amp or plate D made preferably of some non-metallic material has the rear end thereof positioned by a pin 33 on head A and ha'sthe'forwarii end thereof held against vertical'motion'inainanner to be described. A leaf spring F is secured-asat 3| to the carrier 2! and exerts (a force toward the head A for the purpose of holding the parts A-D in close relationship. A stud 32 onthe'forward end of movable cutter C is connected to the lower end of 'rod 26 so that whencthecutting and clamping unit 20 is movedrearwardiy the cutting edge 534 a of blade C will move downwardly and form a bight with the -cutting'edge 35 on the bottom 'of stationary blade B. The thread W enters this-bight asthe shuttle moves forwardly with the lay'notshown, and upon resetting of the mechanism to its normal forward position, the rod 2-3 causes :closing of the cutterjaw'C to sever-the weftW. =The reanpar't of blade C moves upwardly along :the adj acent-surface of clamp D to hold the weft 'thread between the parts C and D.

'flhetmatterzthus far' described, except as noted hereinafter, .is constructed and operates in :the usual manner.

In carrying my inventionfintoieffect :I:provide aniauxiliaryiclamp E'h'aving azforwardly extendingarm'fl; perforated as at' l i. to receive the screw or stud 32. Clamp E has arelatively:iargehoi'e 4*2ither'ein'andthasa rearwardly projecting finger flzprovide'd with?a;preferablyupwardly'andarearwardly extended rounded surface 42. 'Th'eipart of the :clamp-iE behind the :hole 422 iswidened as at #Stoireceiveathe lthrust'iof'thezfoot or lower end wrofathefleafspring F.

A: screw for ipivot stu'd has a :head $9 at one endithere'of.and'hasthelother rendzthereof threadedratx5l rand :tappedinto the head A. A nut-52 holds the screw "H in fixed "adjusted po-sition on t'hehea'd A. The screwpasses' through a hole' 53 in :the :stationary cutter B located intermediate theifrontand back ends orthe t'oped-ge-dfsaid cutter B, thereby cooperating -with a shoulder or ledge 54 Jon headA to position the stationary blade. The :cutter C also has a pivot hole '55 throughwhich-thescrew'I-I passes. The holes 53 and 55 are only slightly larger in diameter than thei'diameter'of thescrew Hand thelatteristhe pivot around which blade C swings.

surrounding the screw H is a bushing or sleeve G which :extends through a relatively large hole 56. InitheIprimary cIam-p D and also through the hole. The sleeve G constitutes a pivotfor the auxiliary-clamp -E,- and engagesth'e inner end of a compression spring 5'l the outer end of which engagesuthe screw-headed. The bushing G has-its inner end held by spring 51 against the pivoted blade Cto force L-thelatter against-the stationary blade B. When the parts are assembled as shown in:Fig.:51the spring Fexerts a pressureon 4 all of the parts B-E forcing them toward the head A.

The rearwardly projecting finger 43 of the auxiliary clamp E slides downwardly along the rear part of the outer surface of the primary clamp D when the unit 28 swings rearwardly, thereby forming a thread receiving notch 58 with the primary clamp. When thread W moves forwardly it enters this notch and also the bight. formed by the cutter blades, and as unit 20 moves forwardly the blade C and clamp E will be swung in'a clock- Wise direction relatively to head A' as viewed in Fig. 2, thereby causing raising of the parts 34 and $43 of the moving cutter C and clam E, respective- .ly. .The .finger .43 of the auxiliary clamp is so Ishaped that during upward movement thereof incident to forward movement of the unit or mechianismdflit willi bendthe thread around clamp D, raising th'e thread-and pulling from the shuttle eye. During this operation the auxiliary clamp pulls ofi .an extra length of the thread prior to cutting of the thread by the blades B and C. At the-end (if the cutting operation therefore as the unit 20 is still in rearward position but moving toward itsforwardiposition.the strand W will textendidownwardly along the blade finger r34 zalong the primary clamp D,'un'der the:latter,:and:then upwardly between 'therclampsrD andi-Ertoxthe :top rounded edge 44 of thefi'nger-M. Stran'd WWill then extend to the selvage. "Bi-3631156101. th'eshape andtime of operation of-the finger 43 a: greater length of the strand W 'will be'hel'drin contact with'the 'primary' clamp Dthan'h'as been possible heretofore, this increase being represented :by that -.-partof the thread extending zbetween 'the clamps-D and-E. Asithe .unit 2i!:corripletes'its forward :motion it moves away from theffell f as aiready described, and if the weft iis relativlyzinelastic it may slidealong the clampsD,'-'butibecause of-the increased :amount of" the thread-Them between'the clamp the strand W"can2slidela:considerable distance along the :primarytblamp-Iand still remain in clamped position between :the clamps D- nd E.

From ?the foregoing it will'be. seenithat :Iihave provided asimpleform of auxiliaryiclamp which serves to pull offa given'length' ofweftffrom the bobbin being transferred before th'e thread is cut bytheblades-B and C. This'additional length of thread lp'ermits aslarger slippage of the thread along the clamp 'D without being detached from the 'mechanism 20 than has heretofore been-possible. iclamp 'E movestransversely oftth'ethread and bonds it up along :clamp D. Itwill also 'be seen -that the bushing or sleeve iG'serves :as "a pivotlfor the auxiliary clamp 1 and also transmits the force-of'spring sl againstithe movableicutter blade C. Furthermore, this bushing also serves tozposition the forward end of the-"clamp D andzcooperates with the pins!) -.to hold blamp Diin correct vertical position while at the same -time permitting'said clampto slide along said bushing into close 'relationshipwi-th respect 'to' the moving cutter C.

Having thus 'described my invention it will be seen that changes and modifications may 'be made therein by those skilled in'the-art without departingfrom the spirit and scope'oftheinvention and I' do not wish to belimited tothe details herein disclosed, but what Iclaim: is:

An auxiliary thread clamp for a loom thread cutting. and clamping mechanism having a -carrierform'edwith a supporting head provided with aplatemountedon a pivot studandJa' pin spaced therefrom, said carrier having mountedthereon'a 5 spring tending to flex toward the head, said clamp having a pivot, hole therethrough' fitting the stud and an operating arm extending forwardly from said hole, a rearwardly extending clamping finger having an upwardly facing edge terminating at a distance from the pivot hole less than the distance between said stud and pin, and said clamp having a portion between said finger and hole to engage said spring.

RICHARD G. TURNER.

REFERENCES CITED The following references are of record in the file of this patent:

Number 6 UNITED STATES PATENTS Name Date Kelley May 1, 1906 Beaverstock July 18, 1916 Stafford Sept. 1, 1925 Moore Apr. 6, 1926 Payne Sept. 3, 1929 Dion Feb. 10, 1931 Irons Aug. 17, 1943 Miller Sept. 21, 1943 

